Hello,
You will need to be fully examined by a physician such as a
neurologist or neuro-otologist. However, there are a couple of possibilities.
1. Your blood pressure may be dropping precipitously while standing or walking (Vasovagal Reaction).
2. You may have
orthostatic hypotension due to medications,
dehydration,
hypoglycemia, or infection (check for Bladder infection, Occult Pulmonary process).
3. You may have some type of cardiac rhythms such as atrial
fibrillation or ventricular flutter or tachycardia
4. You have Meniere's disease versus benign paroxysmal positional vertigo although your reported duration of episodes is much more likely to be an attack of Meniere's rather than BPPV which only lasts moments and usually gets better when the body maintains its position for a moment.
Bottom line is you need to provide a bit more information if a firm diagnosis is to be reached, and get some labs and diagnostics performed or you need to go to a doctor for an examination and history such as I mentioned at first.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. Dariush Saghafi